crpcut is the Compartmented Robust Posix C++ Unit Test system. crpcut (pronounced "Crap Cut") runs all test cases in their own process and their own working directory, which makes it perfectly normal to test that asserts do trap, and the test suite continues even in the event of an unexpected SIGSEGV. By using the C++11 features long available in GCC, the tests are extremely easy to write.
Coco is a code coverage utility for Ruby. It can be used from RSpec or unit/test with a simple "require 'coco'". It works with standalone Ruby or with Rails. It displays the names of files that are uncovered on the console, builds a simple HTML report, and reports sources that have no tests. It is UTF-8 compliant, configurable via a simple YAML file, and has colorized console output.
ytest is a PHPUnit extension, based on the PHP extension "runkit", that allows you to replace static, private, and global functions with fakes, stubs, or mocks. This eases the automated testing of PHP applications that weren't written in a TDD fashion (i.e. test-first). It can also be helpful on projects where many methods are kept private, or projects that don't use OOP so much. ytest has already been used to "test after" (as opposed to "test first") some real-life commercial projects, and has proven useful. It needs PHP >= 5.2.